Thermosiphon liquid circulating heating system



May 7, 1946. M. RESEK THERMOSIPHON LIQUID CIRGULATING HEATING SYSTEMFiled Jan. 15, 1945 2 Sheets-Sheet l 0 M 0 n :a u o 2:713; w w 0 Z 2 5 mF JD 2 i a Z 2 INVENTOR. BY M M 0m (\AQAJY HTTOIPNEYti May 7, 1946. M.RESEK 2,399,942

THERMOSIPHON LIQUID CIRCULATING HEATING SYSTEM Filed Jan. 15, 1945 2Sheets-Sheet 2.

A rroe/v 5 Patented May 7, 1946 THERMOSIPHON LIQUID CIRCULATING HEATINGSYSTEM Marc Resek, Cleveland Heights, Ohio, assignor to Perfection StoveCompany, Cleveland, Ohio, a corporation of Ohio Application January 15,1945, Serial No. 572,919

9 Claims. (01. 123-1425) This invention relates to heating systems ofthe circulating liquid class that are especially suited to the heatingof internal combustion engines and their appurtenances for the purposeof facilitating the starting of the engine during cold weather, and forprotecting the engine and associated equipment from damage by exposureto extremely low temperatures between engine operations.

The present invention is quite similar to that which forms the subjectmatter of my copending application Serial No. 572,918, filed January 15,1945, but is distinguished therefrom by its thermosiphon principle ofoperation. The circulation of liquid in the system of the otherinvention depends on the liquid being elevated by vapor action to a highpoint in the system from which it gravitates.

In order to convey a better understanding of my present improvements, Ishall first describe briefly the ordinary thermosiphon liquidcirculating heating system as employed on military and other vehiclesfor engine heating purposes and point out certain undesirable featuresthereof, the elimination of which is the primary object of my invention.

In order to properly heat an engine by means of the ordinarythermosiphon circulating system, it is necessary to supply the heatedliquid to the bottom of the water jacket or coolant space of thecylinder block, as otherwise the hot liquid at the top of said jacket orspace would cause the thermostatic valve, now commonly used in enginecooling systems, to open and pass the hot liquid into the radiatorinstead of circulating it through said jacket or coolant space, thusrendering the heating of the engine very slow and ineffective. Toaccomplish the introduction of the hot liquid to the bottom of thecoolant space, the top of the heat exchanger or circulating element ofthe heater has to be situated below the point of entrance of the liquid,such point usually being provided by the drain opening or pumpconnection. This arrangement places the heater so low with respect tothe engine that it is inaccessible except from underneath the vehicleand, because of its location, the heater is exposed to the action ofroad dirt, mud, snow, slush and water.

Also, in the use of the ordinary thermosiphon circulating system, whenit is desired to heat the oil pan of the engine, and/or the electricbattery that supplies current for ignition and other purposes, the hotliquid is first circulated through the water jacket or coolant space,which has a very large radiating surface, before it is conveyed to theheat dissipating or delivery unit or units associated with the oil panand/or battery, and because of this sequence, it requires such a longtime for the hot liquid to reach said units that quick heating isimpossible of achievement. This undesirable condition is sometimesremedied to a measurable extent by providing a small bypass tube throughwhich a part of the hot liquid is conveyed directly to the unit or unitsaforesaid.

Obviously, it is highly desirable to locate the heater at ahigherelevation with respect to the engine than is possible in the systemabove described, and it is the principal object of my invention toprovide an improved thermosiphoncirculating system that will ermit ofsuch location of the heater.

While this same end is attained in the vapor-lift system disclosed andclaimed in my companion application above referred to, the presentinvention has the advantage over the other that the heat exchanger orcirculating element of the heater is always kept full of liquid whichresults in faster circulation at lower temperatures.

The foregoing objects and advantages, with others that will appear asthis description proceeds, are attained in the embodiment of theinvention illustrated in the acompanying drawing wherein Fig. 1represents a side elevation of an internal combustion engine equippedwith my improved thermosiphon circulating heating system, the view beingin the nature of a diagram, and showing the system as including heatdissipating or delivery units in heating relation to the oil pan of theengine and to the electric battery; Fig. 2 is an enlarged centralvertical section through the vent chamber of the system shown in Fig. 1;Fig. 3 is a view, similar to Fig. 2, illustrating a modified form of thevent chamber, and Fig. 4 is a view, similar to Fig. 1, showing asomewhat diiierent arrangement of conduits.

In the drawings, the engine is designated generally by the referenceletter E, and the coolant space-that is, the water jacket of thecylinder block-is designated e. Said space is a part of the liquidcirculating cooling system of the engine, which system includes also theradiator R, and said coolant space is in circuit with the radiatorthrough the usual connections 1: and e The connection e leads from thetop of the coolant space to the corresponding part of the radiator,while the connection e leads from the bottom of the radiator to thelower portion of said space and includes the usual circulating pump, theportion of the connection e between the pump and said coolant space, inthe present instance, being formed by a pipe e. The oil pan of theengine is designated e.

The heating system includes a heater I that comprises a heating means orcombustion device I, and a heat exchanger l that consists of acirculating element or coil. The system also embraces, as an essentialpart thereof, a vent chamber 2.

In the embodiment of the system shown in the drawing, heat dissipatingor delivery units 3 and 4 are included, the former being disposed inheating relation to the oil pan c and the latter in heating relation tothe electric battery B. The battery B provides the source of current forthe starting and ignition circuits of the engine, and the lighting andother circuits of the vehicle. As will be readily understood, each ofthe units 3 and 4 includes a liquid passage having an inlet and anoutlet.

The vent chamber 2, shown in central vertical section in Fig. 2,comprises a vessel designated 2 and a stand pipe 2 Said vessel may be ofcylindrical form, and in the embodiment illustrated, it is substantiallysemi-spherical at top and bottom. The stand pipe 2 extend upward- 1ythrough the bottom of said vessel, substantially central thereof, andterminates adjacent the top of the vessel. The stand pipe is providedwith an aperture 2 adjacent the bottom wall of the vessel 2 so as toestablish free communication between the interior of the stand pipe andthe surrounding part of the chamber. A relatively small pipe 2 leadsfrom the upper portion of the chamber 2 and is vented to the coolingsystem of the engine, according to the present arrangement, into the topor the radiator R. The vent chamber is located well above the plane ofthe heater 1 and is so related to the cooling system of the engine thatthe plane of the maximum liquid level of the cooling system isintermediate the top and bottom of said chamber, desirably nearer thebottom than the top. Thus, a liquid space is provided in the bottomportion of the vent chamber, with a vapor space thereabove, as clearlyshown in Fig. 2.

A conduit 5 has communicative connection with the outlet of the heatexchanger l and leads therefrom upwardly to and communicates with thebottom of the stand pipe 2*, said conduit continuing, according to thepresent arrangement, to the inlet of the liquid passage of the heatdissipating or delivery unit 3 that is arranged in heating relation tothe oil pan e A conduit 8 leads from the outlet of said unit to theinlet of the unit 4, and communicative connections are made between theoutlet of the latter unit and the bottom portion of the coolant space eof the engine through a conduit 1. A conduit 8 leads from the topportion of said coolant space to the inlet of the heat exchanger l thesame including a trap 9 that prevents liquid from being forced by vaporpressure from the heat exchanger l through the conduit 8 back into thecoolant space of the engine.

Assuming that liquid stands in the cooling system of the engine at aboutthe elevation indicated by the dot-and-dash line a, a liquid levelcorresponding thereto prevails in the heating system, more specifically,in the vent chamber 2, the liquid level therein being indicated at b inFig. 2. Accordingly, liquid is present in all conduitsof the heatingsystem, as well as in the liquid passages of the units 3 and 4, in thecoolant space e, and in the heat exchanger 1.

With the heat ing means or combustion device l in operation,

the liquid in the exchanger is heated and, as a consequence thereof,rises through the conduit 5, any surging of the liquid caused by boilingbeing manifested by a rise and fall of the liquid in the stand pipe 2".Air or vapor bubbles created in the heated liquid will escape throughthe top of the stand pipe into the vapor space of the vent chamber 2 andwill pass out through the pipe 2 to the cooling system of the engine.The stand pipe, which extends well above the liquid space of the ventchamber, prevents any of the liquid from being blown out of the chamberthrough the pipe 2 notwithstanding a pronounced sur ing action in thestand pipe or a boiling effect caused by the air or vapor bubbles.Displacement of liquid out of the top of the stand pipe under theconditions just mentioned is precluded by the presence of the aperture 2in said pipe through which free communication prevails between theliquid space of the chamber and the interior of the pipe.

By thermosiphon action, flow of the hot liquid will continue on throughthe descending branch of the conduit 5 and, passing through the liquidspace of the unit 3, will flow on through the conduit 6, the liquidspace of the unit 4, and conduit 1 to the bottom Portion of the coolantspace e. The heated liquid rising within said space will displace liquidfrom the top portion thereof through the conduit 8 which conveys theliquid to the inlet of the exchanger I".

Thus it will be seen that a constant fiow of liquid will continue withinthe system in the direction described as long as heat is supplied to theexchanger by the heating means or combus tion device I; and circulationwill start as soon as the liquid in the exchanger becomes warm enough torise through the conduit 5. By variously arranging the liquid conductingmeans or conduits, hot liquid may be carried to any point desired belowthe vent chamber, although the conduit arrangement must be such thatthere are no upturned loops in which air or steam may collect.

Instead of connecting the units 3 and 4, and the coolant space of theengine-which is, in effect, another heat dissipating or delivery unitina single circuit as shown in the drawing, parallel circuits may be usedso that the'hot liquid from the heat exchanger, after passing the standpipe of the vent chamber, may flow directly to each of the units andreturn from each to the inlet of the heat exchanger. Such an arrangementis illustrated in Fig. 4, where the conduit 5, that extends from theoutlet of the heat exchanger I to the bottom of the stand pipe 2 andthence to the inlet of the heat dissipating or delivery unit 3, hasbranches 5 and 5 that lead, respectively, to the inlet of the coolantspace 6' of the engine and to the inlet of the heat dissipating ordelivery unit 4. The respective outlet conduits 6 and I of said units 3and 4, and the outlet conduit 8 of the coolant space e dischargedirectly into a manifold In that constitutes the inlet of the heatexchanger l Examples of other arrangements are disclosed in my companionapplication above identified.

In Fig. 3 I have shown a modification of the vent chamber, designatedgenerally by the reference numeral 20. In this form,'the stand pipe 20terminates at its junction with the bottom wall of the vessel 20, andbubbles rising through said pipe are immediately liberated to the bodyof liquid in the vessel and ascend to the vapor space thereabove fromwhere the air as gases,

and a'possible small quantity of vapor sustained thereby, escape throughthe vent pipe 20.

Having thus described my invention, what I claim is:

1. In a heating system of the classset forth, a heat exchanger having aliquid passage provided with an inlet and an outlet, a source of heat inheating relation to said heat exchanger, a vent chamber located at ahigher elevation than said heat exchanger the bottom portion of whichconstitutes a liquid space and the portion thereabove a vapor space, astand pipe opening into said vapor space a substantial distance abovethe liquid space and having an aperture adjacent the bottom of thechamber through which the interior of the pipe communicates with saidliquid space, means venting the vapor space, a heat dissipating unitbelow the plane of the vent chamber, said unit having a liquid passage,and liquid conducting means leading from the outlet of the heatexchanger upwardlyto and communicating with the stand pipe andcontinuing therebeyond to provide a circuit including the liquid passageof said unit and leading to the inlet of the heat exchanger.

2. In a heating system of the class set forth for use with an internalcombustion engine incorporating a coolant space and a liquid circulatingcooling system including said space, a heat exchanger having a liquidpassage provided with an inlet and an outlet, a source of heat inoperative relation to said heat exchanger, a vent chamber located at ahigher elevation than said heat exchanger and so related to the coolingsystem that the plane of the maximum liquid level in the latter isintermediate the top and bottom of said chamber so as to provide aliquid space within the bottom portion of the chamber and a vapor spacethereabove, means venting the vapor space to the cooling system, andliquid conducting means leading from the outlet of. the heat exchangerto the bottom portion of the coolant space of the engine, other liquidconducting means leading from the top portion of said space to the inletof said heat exchanger, the first mentioned liquid conducting meansincluding a part rising from the outlet ofthe exchanger, and a standpipe communicating with the top of said part and opening into the vaporspace of the vent chamber, said stand pipe having an aperture throughwhich its interior communicates with the liquid space of the chamberadjacent the bottom of the latter.

3. In a heating system of the class set forth for use with an internalcombustion engine incorporating a coolant space and a liquid circulatingcooling system including said space, a heat exchanger having a liquidpassage provided with an inlet and an outlet, a source of heat inoperative relation to said heat exchanger, a vent chamber located at ahigher elevation than said heat exchanger and in such relation to thecooling system that the plane of the maximum liquid level in the latteris intermediate the top and bottom of the chamber so as to provide aliquid space adjacent the 'bottom of the chamber and a vapor spacethereabove, means venting said vapor space to the cooling system, astand pipe rising through the bottom of said chamber and terminating aconsiderable distance above the plane of said liquid level, said standpipe having an aperture adjacent the bottom of the chamber through whichcommunication is established between the interior of the stand pipe andsaid liquid space, and liquid conducting means leading from the outlet01' the heat exchanger to the bottom of the stand pipe and thence to thebottom portion of the coolant space of the engine, and liquid conductingmeans leading from the top portion of said space to the inlet of theheat exchanger.

4. In a heating system of the class set forth for use with an internalcombustion engine incorporating a coolant space and a liquid circulatingcooling system including said space, a heat exchanger having a liquidpassage provided with an inlet and an outlet, a source of heat inoperative relation to said heat exchanger, a vent chamber located at ahigher elevation than said heat exchanger and in such relation to thecooling system that the plane of the maximum liquid level in the latteris intermediate the top and bottom of the chamber so as to provide aliquid space adjacent the bottom of the chamber and a, vapor spacethereabove, means venting said vapor space to the cooling system, astand pipe rising through the bottom of said chamber and terminating aconsiderable distance above the plane of said liquid level, said standpipe having an aperture adjacent the bottom of the chamber through whichcommunication is established be-- tween the interior of the stand pipeand said liquid space, and liquid conducting means leading from theoutlet of the heat exchanger to the bottom of the stand pipe and thenceto the bottom portion of the coolant space of the engine, and liquidconducting means leading from the top portion of said space to the inletof the heat exchanger, the last mentioned means including a trap forpreventing reverse flow of liquid through the heat exchanger.

5. In a heating system of the class set forth for use with an internalcombustion engine incorporating a coolant space and a liquid circulatingcooling system including said space, a. heat exchanger having a liquidpassage provided with an inlet and an outlet, a source of heat inoperative relation to said heat exchanger, a vent chamber located at ahigher elevation than said heat exchanger and being so related to saidcooling system that the plane of the maximum liquid level in the latteris betweenthe top and bottom of said chamber, thereby to provide withinthe latter a liquid space adjacent the bottom of the chamber and a vaporspace thereabove, means venting said vapor space to the cooling system,a stand pipe rising through the bottom of said chamber and terminating aconsiderable distance above the plane of said liquid level, said standpipe having an aperture adjacent the bottom of the chamber through whichits interior communicates with the liquid space, a heat dissipating unitfor heating an appurtenance of the engine, the same having a liquidpassage provided with an inlet and an outlet, liquid conducting meansleading from the outlet of the heat exchanger upwardly to andcommunicating with the bottom of the stand pipe and providingtherebeyond a circuit including said unit and the coolant space of theengine and leading to the inlet of the heat exchanger.

6. In a heating system of the class set forth for use with an internalcombustion engine incorporating a coolant space and a liquid circulatingcooling system including said space, a heat exchanger having a liquidpassage provided with an inlet and an outlet, a source of heat inoperative relation to said heat exchanger, a vent chamber located at ahigher elevation than said heat exchanger and being so related to saidcooling system that the plane of the maximum liquid level in the latteris between the top and bottom of aid chamber, thereby to provide withinthe latter a liquid space adjacent the bottom of the chamber and a vaporspace thereabove, means venting said vapor space to the cooling system,a stand pipe rising through the bottom of said chamber and terminating aconsiderable distance above the plane of said liquid level, said standpipe having an aperture adjacent the bottom of the chamber through whichits interior communicates with the liquid space, a heat dissipating unitfor heating an appurtenance of the engine, the same having a liquidpassage provided with an inlet and an outlet, liquid conducting meansleading from the outlet of the heat exchanger upwardly to andcommunicating with the bottom of the stand pipe and thence to the inletof said heat dissipating unit, other liquid conducting means leadingfrom the outlet of said unit to the bottom portion of the coolant spaceof the engine, and further liquid conducting means leading from the topportion of said coolant space to the inlet of the heat exchanger.

7. In a heating system of the class set forth for heating an internalcombustion engine and an electric battery associated therewith, saidengine incorporating a coolant space and a liquid circulating coolingsystem including said space, a heat exchanger having a liquid passageprovided with an inlet and an outlet, a source of heat in operativerelation to said heat exchanger, a vent chamber located at a higherelevation than said heat exchanger and so related to the cooling systemthat the plane of the maximum liquid level in the latter is between thetop and bottom of said chamber thereby to provide a liquid spaceadjacent the bottom of the chamber and a vapor space thereabove, a standpipe opening at its upper end into the chamber a considerable distanceabove the plane of said liquid level, said standpipe having an apertureadjacent the bottom of the chamher through which its interiorcommunicates with the liquid space of the chamber, a heat dissipatingunit for heating the oil pan of the engine, a second heat dissipatingunit in heating relation to the battery, and liquid conducting meansleading from the outlet of the heat exchanger upwardly to andcommunicating with the bottom of the stand pipe and therebeyondproviding a circuit including said dissipating units and leading tothe'inlet of the heat exchanger.

8. In a heating system of the class set forth for heating an internalcombustion engine and an electric battery associated therewith, saidengine incorporating a coolant space and a liquid circulating coolingsystem including said space, a heat exchanger having a liquid passageprovided with an inlet and an outlet, a source of heat in operativerelation to said heat exchanger, 8

vent chamber located at a. higher elevation than said heat exchanger andso related to the cooling system that the plane of the maximum liquidlevel in the latter is between the top and bottom of said chamberthereby to provide a liquid space adjacent the bottom of the chamber anda vapor space thereabove, a stand pipe opening at its upper end into thechamber a considerable distance above the plane of said liquid level,said stand pipe having an aperture adjacent the bottom of the chamberthrough which its interior communicates with the liquid space of thechamber, a heat dissipating unit for heating the oil pan of the engine,a second heat dissipating unit in heating relation to the battery,liquid conducting means leading from the outlet of the heat exchanger toand communicating with the bottom of the stand pipe and thence to theinlet of one of said heat dissipating units, another liquid conveyinmeans leading from the outlet of the last mentioned unit to the inlet ofthe other unit, liquid conveying means leading from the outlet of saidother unit to the bottom portion of the coolant space of the engine, andliquid conveying means leading from the top portion of said coolantspace to the inlet of the heat exchanger.

9. In a, heating system of the class set forth, a heat exchanger havinga liquid passage provided with an inlet and an outlet, a source of heatin heating relation to said heat exchanger, a vent chamber located at ahigher elevation than said heat exchanger the bottom portion of whichconstitutes a liquid space and the portion thereabove a vapor space, astand pipe opening into said chamber, means venting the vapor space, aheat dissipating unit below the plane of the vent chamber and in heatingrelation to an object to be heated, said unit having a liquid passage,and liquid conducting means leading from the outlet of the heatexchanger upwardly to and communieating with the stand pipe andcontinuing therebeyond to provide a circuit including the liquid passageof said unit and leading to the inlet of the heat exchanger,

MARC RESEK.

